Acetylene generator with vibrating feed valve



Jan. 16, 1945. c. F. SMITH 2,367,240

ACETYLENE GENERATOR WITH VIBRATING FEED VALVE Filed June 27, 1940 3Sheets-Sheet 1 INVENTOR ATTORNEY.

Jan. 16, 1945. c -F SMITH 2,367,240

ACE TYLENE GENERATOR WITH VIBRATING FEED VALVE Filed June 27, 1940 '3Sheets-Sheet 2 W. ll

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Patented Jan. 16, 1945 UNITED STATES PATENT OFFICE .ACETYLENE GENERATORWITH VIBRATING FEED VALVE Carl F. Smith, West Alexandria, OhioApplication June 27, 1940, Serial No. 342,665

Claims. (01. 48-533) This invention relates to acetylene generators, andparticularly to mechanism for maintaining a uniform flow of carbide,whereby the service line pressure is kept more uniform.

The improvements are embodied in a generator of the type wherein acarbide feed valve is operated to closed position we rise in generatingtank pressure applied to one side of a diaphragm, and to open positionby* a spring under stress applied to the opposite side of the diaphragm.

Generators of this class areusually operated with coarse carbidegranules of not very uniform size, and one of the obstacles tosatisfactory operation is that when the tank pressure falls, allowingthe spring to open the feed valve, the coarse granules are usually sostacked around the valve that it must open quite wide before any carbidefalls through it, and then, when it does fall, the quantity released isin excess of that desired for uniform gas production.

It is therefore an object of this invention to provide means whereby thefeed valve mechanism will be kept in a state of vibration, to the endthat the granules in the immediate vicinity of the feed valve will bekept in a loosened state and therefore will be fed more evenly.

The idea of providing more uniform feeding of the carbide, by vibratingthe feed valve, is not broadly new, but the mechanism heretoforeproposed to achieve this result fails to take advantage of the meansavailable to create a degree of vibra-' tion adequate to produce thebest results.

It is therefore another object of this invention to drawthe valvevibrating pressure from the point where vibration is greatest, and applyit to the valve in a more direct and effective manner than hasheretofore been known.

That these and other objects and advantages are achieved in theembodiment hereinafter disclosed will be apparent as the invention isfurther described with reference to the drawings, wherein,

Fig. 1 is an elevational view, partly in vertical section, through agenerator embodyingthe improved vibrating mechanism.

Fig. 2 is a view similar to Fig. 1, but showing a slight variant of themechanism, and

Fig. 3 shows a further modification in the structural details of thedevice.

Similar numerals refer to I similar parts throughout the drawings.

The generating tank It is conventional having the usual water fillerplug l2 located to govern the depth of the water in the tank, the usualdrain cock l4, and agitator crank IS. The top of the tank is flangedinward at It and carries the hinge bolts 20 for clamping the carbidehopper 22 in place. A gasket 24 makes a pressure tight joint between thehopper and the tank.

. The hopper 22 comprises a hoppertop 26, a hopper bottom 28 and acylinder 36 preferably made of Pyrex glass clamped between the top andbottom by the bolts 32. Gaskets 34 make pressure tight joints betweenthe several parts.

The hopper top 26 has a box-like compartment 36 which houses the feedregulating mechanism, the upper side of-the compartment being closed bya cover plate 35 held on by screws 31. A feed regulating spring 38 iscontained in a spring housing 40 which is clamped to the underside ofthe hopper top 26 by screws 42. A feed regulating diaphragm 44 isinterposed between hopper top 26 and housing 40, and thus serves also asa gasket between these parts. A hand screw 46 in the bottom of thehousing may be operated to regulate the tension of the spring 36. Smallholes 45 connect the inside of the housing 40 to the atmosphere.

A post 48, having an integrally extending stem 50, is secured in thecenter of the feed regulating diaphragm, the diaphragm being heldbetween washers 52 by a nut 54. The stem is vertically slidable in thehand screw 46.

A second post 56 is secured at its lower end in the floor of the hoppertop 26, a lever 58 being fulcrumed to the upper end of the post by ahinge pin 60. The shorter arm of the lever 58is hinged at 62 to the post48, while the longer arm is arranged to give vertical movement to thestem 64 of the feed valve.

At the lower end, the stem 64 carries the valve heads 66 and 68. A largetube 10 depends from the floor of the hopper top 26 surrounding the stem64 at some distance therefrom. .The tube 10 is flared at its lower endto deter packing of the carbide about the valve heads. A flexible washer12 provides a suitable seat for the lower valve head 66. A splash tube14 is supported on a hub on the underside of the hopper bottom 26 toprevent splashing of water on the valve head and seat when the device ismoved.

A screw plug in the wall of the hopper bottom may be removed for fillingthe hopper with carbide. A safety screw 16 extends through a hub 18 inthe cover plate 35 and this screw may be used to forcibly raise thelower valve head 66 against the seat 12 to render thedevice inoperative.The screw 16 extends into a metal bellows 80 which is closed at thebottom and has its open end soldered or similarly secured to theunderside of the hub 18, whereby leakage around the screw 16 isprevented.

The parts thus far enumerated and described are substantially the samein Figs. 1, 2 and 3, but the means for vibrating the feed valve stemsdifler in the several embodiments.

In Fig. 1, the vibrating diaphragm 82 is clamped between the dome 84.and ring 86 by the bolts 88. The dome has an ear 90 by which it ishinged to the end of the lever 58 by the pin 92. At the center, thediaphragm 82 is attached to the valve stem 64 by clamping it betweenwashers 94 by nuts 96, the nuts being threaded onto the valve stem. Atube 98 connects the space within the dome 84 to a source of pulsatingpressure. The underside of the vibrating diaphragm 82 is exposed to thegas pressure of the generating tank I0 and hopper 22, and since the tankpressure is usually several ounces higher than the source of pulsatingpressure, a light compression spring I00 within the dome 84 compensatesfor this difference.

In Fig. 2, the vibrating diaphragm 82 is clamped between the dome I02and ring I 04 by bolts 88. The ring I04 has an ear I08 by which it ishinged to the lever 58 at a point I08. At the center, the

vibrating diaphragm is held on a post I I0 between washers II2 by a nutII4, the nut being threaded onto the post. The lower end of the post H0is hinged at 6 to the lever 58. The outer end of the lever 58 is hingedto the valve stem 64 by a pin II8. A tube 98 connects the space withinthe dome I02 to a source of pulsating pressure. The underside of thevibrating diaphragm 82 is exposed to the gas pressure of the generatingtank I 0 and hopper 22, and since the tank pressure and pulsatingpressure may have a different value a light compression spring I00 isprovided.

On Fig. 3, the vibrating diaphragm 82 is clamped between the dome I20and the ring I22 by screws I 24. The ring is welded or similarlyfastened to the tube 10 over an opening I25 in the tube. The center ofthe vibrating diaphragm is held to a post I26 between washers I28 by anut I30. A long hub I32 has its outer end closed and its inner open endwelded or similarly joined to the wall of the tube 10. The post I28 isslidably fitted to the inside of the hub I32, and, at its middleportion, has a small hub I33 through which the valve stem 84 extendsslidably. A tube I 34 connects the space within the dome I20 to a sourceof pulsating pressure, a portion I35 being flexible. The outer side ofthe vibrating diaphragm is exposed to the gas pressure of the generatingtank I0 and hopper 22 through the opening I25. A light extension springI36 compensates for the diiference in pressure on the two sides of thediaphragm,

Generators of the class herein shown are usually provided with a flashback arrester which comprises a small tank I38 held to the main tank I0brackets I40 and containing a lower water compartment I42 the level ofwhich is fixed by the position of a filler plug I44, a middlecompartment I48 which carries the bailie plates I48 and an upper ordrying compartment which contains the filter material I50. The cap I52on the top of the flash back tank supports the pressure gauge I54, thesafety valve I56 and the service valve I58 from which gas is drawn foruse in various applicances such as welding torches, floodlights, and soforth.

' In Fig. 1, the tube 98 connects the space within the dome-shapedcasing 84 to the space in the upper portion of the flash back tank I 38.A small portion of tube 98 as at I60, and a larger portion as at I62, ispreferably made of flexible material, the remainder being of metal. Themetal part should be welded where it emerges from the tank I0 and whereit'enters the tank I38.

Still referring to Fig.1, a large pipe I64 connects the portion of thetank I0 above the water line to the bottom of the tank I38, the gasentering the tank I38 through a check valve I66. Valve I66 comprises abody I68 having a seat I10 wherein a ball I12 rests by gravity, and aperforated cap I14 t limit upward movement of the ball. A drain plug I16is provided in the bottom of the valve body.

In Fig. 2, a large pipe I18 connects the upper portion of the tank I0 tothe bottom of the tank I38. The drain plug I in the bottom of tank I 38is conventional. A flash back check valve I82 is inserted in the pipe I18 close to where it emerges from the tank I 0. Valve I 82 comprises abody I84 with a ball I86 on a seat I88 and a guide cap I90 for the ball.

Still referring to Fig. 2, the tube 98 connects the space within thedome-shaped casing I02 into the large pipe I18 near its upper end. Asmall part I92 and a larger part I94 of the tube 98 should be' offlexible material and the remaining portion preferably of metal. Themetal part should be welded where it emerges from the tank l0 and whereit enters the pipe I 18.

In Fig. 3, the large pipe I96 which connects the upper portion of tankI0 to the bottom of the flash back arrester tank I38 has interposedtherein two valves I66 and I82 which may be like the valves in Figs. 1and 2, respectively. The tube I 34 which connects the space within thedome-shaped casing I20 to the space within the top of the flash backtank I38 may have the end portions made of metal and the intermediateportion of flexible material. The one end should be welded where itemerges from the tank I0 and where it enters the tank I38.

The check valves I66 and I82 are primarily provided to arrest a flashback from the service line into the generating tank, but incidentallythe interrupted opening and closing of the valve causes pulsation ofconsiderable magnitude in the pressure within the flash back arrester.The weight of the ball in the check valve will govern the degree ofpulsation, since the pressure in the tank must exceed that in the flashback arrester an amount suiiicient to raise the ball, then when thepressures equalize, the ball drops back onto its seat. It is the rapidrepetition of this performance which causes the pulsating pressure. Whentwo valves are used as in Fig. 3, the pulsation is not only more rapid,but, due to the fact that the movement of the two valves will not besynchronized, the vibration is broken up into more uneven pulsations.

It should be noted that while a check valve which is primarily necessaryto the flash back arrester is made to serve the additional purpose of aninterrupter valve, to cause pulsation of the gas pressure in the linebetween the interrupter valve and the service valve, one of the valves,as in Fig. 3, may be a check valve and the other may be any sort of a.valve which rapidly interrupts the gas flow from the generating tank.and while the loading of a check valveofthe kind herein shown isinherent in the ball, a valve having a lighter valve head may be usedand spring loaded to a degree which will equal the heavier ball.

Operation Theflller plugs I2 and I44 are removed and the tanks fllledwith water to the height shown. When the plug I2 is removed allpressure, in the tank I is relieved. This allows thespring 88 to lowerthe feed valve head 68 until it covers the hopper outlet. 7

The hopper is next removed by loosening the bolts 20, the plug 15 isremoved and the hopper filled with granular carbide, and the hopperreturned to position with the plug 15 drawn up tight.

Generation may now be started by turning down the safety screw 16 untilthe valve heads 66 and 68 are approximately in the position shown in thedrawings, whereupon carbide will fall from the hopper into the tank, gaswill be generated, and when the generated pressure, bearing on the upperside of the regulating diaphragm 44, overbalances the force to which thespring 38 is adjusted, the valve head 66' will be drawn against theflexible seat 12 and generation will for the moment cease. I

During this period of generation, the service valve I58 may have beenclosed. If now the gauge I54 does not show vthe desired pressure, theregulating screw 46 may be turned until the desired pressure isobtained. The screw 16 should now be raised at least as high as theposition shown in the drawings, and left there for all operatingconditions. If, however, it becomes desirable to lock the device againstcarbide flow, while the generator is being moved, or while it is to beout of use for a period of time, this may be done without relieving thepressure in tank I0 by turning the hand 'screw 16 downward far enough tohold the valve head 66' up against the flexible seat 12.

Referring particularly to Fig. 1, the pressure in tank I0 is transmittedthrough pipe I64 and check valve I66, through the water compartment I42,baflle plates I48, and filter I50, to the top of the flash back tankI38.

The check valve I66 should be so proportioned and the ball I12 should beof such weight that it will require an excess pressure in the tank I0,

over that in the top of tank I38, of several ounces before the ball willbe raised to allow a bubble of gas to pass. Since the space for gas inthe tank I38 is limited, a small volume only need be transferredthereinto to make several ounces difierence in pressure. It followsthat, with a normal flow of gas out of the service valve I58 the riseand fall of the ball I12 is as rapid as gravity will return it to itsseat after the gas pressure raises it. This rapid pressure pulsation istransferred through the tube I62, I60, 96 into the domeshaped casing 84,where, acting on diaphragm 82 it vibrates the feed valve stem 64vertically.

It should be noted that pulsation of the vibrating diaphragm 82 isapplied directly to the feed valve stem 64, and that the pressureregulating diaphragm 44 has no part in creating feed valve vibration,while, in devices heretofore proposed, the pulsations of the vibratingdiaphragm are transferred pneumatically to pulsate the feed regulatingdiaphragm which in turn vibrates the 4 feed valve. The loss of vibratingforce through several transfers, when it is only several ounces to beginwith, is a serious objection to the present state of the art.

As the valve head 66 moves away from and back to the seat 12, inresponse to a drop and subsequent rise in pressure in tank I0 due to gasconsumption and regeneration, the continuous vertical vibration oi thefeed valve head 68 keeps the granular. carbide loosened and flowingfreely and uniformly through the valve seat washer 12. The lower flaredend of the large tube 10 prevents too great a weight of carbide settlingon the valve head 68.

In Fig. 2, the pressure in tank I0 is transferred to the top of tankI38, first through the check valve I82 then through the pipe I18. Inthis embodiment of the invention, the pulsating pressure is taken fromthe top of the pipe I18 instead of the top of the tank I38, andtransferred through tubing I94, I92, 98 into the dome-shaped casing I02.As the space within the dome-shaped casing alternately increases anddecreases, the casing must move rapidly up and down with respect to thelever 58. This vibrates the lever which in turn vibrates the valve stem64, but in doing so; it must also slightly vibrate the regulatingdiaphragm 44, although the regulating diaphragm in no sense supplies ortransfers a motive force for vibrating the valve.

In Fig. 3, the pulsating pressure is again taken from the top of theflash back tank I38 and conveyed to the dome-shaped casing I20 throughtubing I35, I34, but in this case the pulsation in the casing I20creates a lateral vibration of the feed valve stem 64 as it is movedvertically by the regulating diaphragm.

It should be noted that, in each of the several embodiments shown, thepulsating pressure within the dome, acting on one side of the vibratingdiaphragm, is directly opposed by the slightly higher pressure in thegenerating tank I0 acting directly on the other side of the vibratingdiaphragm. An advantage of this arrangement results for the reason thatwhen a volume of as is passed by a check valve ball, the pressure'isconsiderably increased in the dome-shaped, casing on one'side of thevibrating diaphragm but is also somewhat decreased on the opposite sideof the diaphragm whereby the vibrating effect of such transfer is thealgebraic sum of the two pressure changes. This effect has notheretofore been obtained.

Having described several embodiments of the invention and the manner inwhich they operate, I claim:

1. In an acetylene gas generator having a generating tank of relativelylarge capacity, a hopper for receiving carbide, a carbide feed valvemovable for controlling the delivery of carbide from said hopper to saidtank, and regulating means including a diaphragm one side of which isresponsive to the pressure of the gas generated in said tank forcontrolling the feed valve to effect regulation of the pressure of thegenerated gas, the combination of a liquid trap flash back arrester, anopen conduit for delivering the generated gas from said tank into saidarrester where it escapes in 'bubbles passing upwardly through theliquid into a space of relatively small capacity above such liquidresulting in variations and pulsations in the gas pressure therein, anda conduit extending from said space above thc liquid to the oppositeside of said diaphragm to make said varying and pulsating pressureeifective upon able for controlling the delivery of carbide from saidhopper to said tank, and regulating means including a diaphragm one sideof which is responsive to the pressure of the gas generated in said tankfor controlling the feed valve to effect regulation of the pressure ofthe generated gas, the combination 01' a liquid trap flash back arresterincorporating a check valve therein, an open conduit for delivering thegenerated gas from said tank into said arrester where it escapes inbubbles passing upwardly through the liquid into a space of relativelysmall capacity above such liquid resulting in variations and pulsationsin the gas pressure therein, and a conduit extending from said spaceabove the liquid to the opposite sideof said diaphragm to make saidvarying and pulsating pressure effective upon said diaphragm withresultant vibration of said diaphragm and of said feed valve.

3. In an acetylene gas generator having a generating tank, a hopper forreceiving the carbide, a carbide feed valve movable for controlling thedelivery of carbide from said hopper to said tank and regulating meansincluding a diaphragm one side of which is responsive to the pressure ofthe as generated in said tank for controlling the movement of said feedvalve to eil'ect regulation of the pressure of the generated gas, thecombination of means for delivering the gas generated in said tank to apoint of discharge, means in the path of discharge of said gas toproduce a pulsating pressure in the discharged gas with respect to thepressure within said tank, means cornmunicating with said pulsatingsource of gas pressure and with the opposite side of said diaphragm toeffect a vibrating movement thereof, and means for mechanicallyconnecting said diaphragm to said feed valve to cause a sidewisevibratory motion thereof.

4. In an acetylene gas generator having a generating tank, a hopper forreceiving canbide, a

carbide feed valve movable for controlling the delivery of carbide fromsaid hopper to said tank, and regulating means including a diaphragm oneside of which is responsive to the pressure of the gas generated in saidtank for controlling the position of said feed valve to eflectregulation of the pressure of the generated gas, the combination ofadjustable means for yieldably applying force to said diaphragm topredetermine the pressure at which said pressure regulating meansoperates, means extending into the pressure zone and having a positiveoperative connection with said carbide feed valve for locking saidcarbide teed valve in closed position, and a flexible bellows enclosingsaid last mentioned means and eilectively' sealing the same againstescape of pressure from said pressure zone.

5. In an acetylene gas generator having a generating tank and adapted tohandle carbide in granular form, the combination of a hopper forreceiving the granular carbide, said hopper having a valve seat defininga feeding opening, a diaphragm one side of which is responsive to thepressure of gas generated in said tank to regulate the supply of carbidethereto, a valve rod operably connected with said diaphragm for movementin response to the generated gas pressure, adjustable spring means formoving said valve and opposing the pressure of the gas on said diaphragmto regulate the gas pressure developed by said generator, a valve membercarried on said rodand movable away from said seat to enlarge saidfeeding opening in response to a reduction in gas pressure, and a secondvalve member carried by said rod in spaced relation with the first saidvalve member leaving a free feeding space be tween said valves fornormal regulated operation, said second valve member being movable to aclosed position against said seat under the action of said spring meanthroughout the normal regulating range of adjustment thereof in responseto abnormal loss of gas pressure from said tank to shut off furtherfeeding of carbide into said hopper.

CARL F. SMITH.

